A novel solvent-free formulation system has been discovered that is capable of enhancing the application, stability, and performance of nitrogen fertilizer stabilizing compositions that are based on n-alkyl thiophosphoric triamides. The existing art that deals with the formulation of n-alkyl thiophosphoric triamides for agricultural applications is based on the use of traditional organic solvents that have a number of limitations related to cold weather stability, toxicity, fertilizer compatibility, cost, and clean-up. The new approach that we have discovered eliminates or significantly reduces these problems and is capable of providing a liquid formulation without the use of solvents.
N-alkyl thiophosphoric triamides (particularly n-butyl phosphorotriamide) (NBPT) are used extensively in applications with urea based fertilizers due to their ability to inhibit the urease enzyme. The urease enzyme is ubiquitous to most soils—and is responsible for the conversion of urea nitrogen to volatile ammonia gas. This volatile form of nitrogen is lost from the soil, thus reducing the amount that is available for plants. The ability of n-alkyl thiophosphoric triamides to provide this inhibition makes for a valuable tool in management of nitrogen fertilizer applications.